Transitional cell cancer of the renal pelvis and ureter that has spread beyond its original location to distant parts of the body is known as metastatic disease. This condition represents an advanced stage of cancer that begins in the specialized cells lining the kidney’s collecting area and the tubes connecting the kidneys to the bladder. When this cancer spreads, treatment becomes more complex, and the outlook for patients changes significantly compared to early-stage disease.
Understanding the Disease and How Common It Is
Transitional cell cancer of the renal pelvis and ureter is a relatively uncommon form of cancer. Transitional cell cancer, also called urothelial carcinoma, starts in special cells that line the inside of the urinary tract. These cells are unique because they can stretch when the area fills with urine and shrink when it empties, much like a balloon that expands and contracts.[1]
The renal pelvis is the central collection area inside the kidney where urine gathers before flowing down into the ureter, a long tube that carries urine to the bladder. There are two kidneys in the body, positioned on either side of the spine above the waist, and each kidney has its own ureter. This type of cancer can develop in the renal pelvis, the ureter, or both locations at the same time.[1]
Transitional cell cancer of the renal pelvis accounts for only about seven percent of all kidney tumors, while transitional cell cancer of the ureter represents just four percent of upper urinary tract tumors. This makes them quite rare compared to other kidney cancers. Transitional cell cancers of the upper urinary tract represent only about ten percent of all transitional cell cancers, as this type of cancer is far more common in the bladder.[3][2]
The disease typically affects older adults, most commonly those aged 65 and older. Men are diagnosed more frequently than women, with males being about twice as likely to develop this type of kidney cancer and four times more likely to get bladder cancer.[2][5]
What Causes This Cancer
Medical researchers do not yet fully understand the exact cause of transitional cell cancer of the renal pelvis and ureter. The disease involves changes in how transitional cells function, particularly in the way they grow and divide to form new cells. When a healthy transitional cell undergoes certain changes, called mutations, it can become a cancer cell. These cancer cells then multiply uncontrollably and can form tumors.[1][5]
Both genetic factors and environmental influences appear to play roles in causing this cancer. While some people may have inherited tendencies toward the disease, external factors like smoking and chemical exposures also contribute significantly to risk. The exact combination of factors that triggers the transformation of normal cells into cancer cells remains an area of ongoing research.[2]
Risk Factors That Increase Disease Likelihood
Cigarette smoking stands out as one of the most significant risk factors for developing transitional cell cancer of the renal pelvis and ureter. People who smoke have a substantially increased risk compared to non-smokers, as tobacco smoke contains harmful chemicals that can damage the cells lining the urinary tract.[1][2]
A personal history of bladder cancer significantly elevates the risk of developing this cancer in the upper urinary tract. Between 30 and 50 percent of people who have had upper tract transitional cell cancer will later develop bladder cancer. When the cancer involves both the renal pelvis and ureter, the likelihood of subsequent bladder cancer jumps to 75 percent.[3]
Occupational exposure to certain chemicals increases risk as well. People who work with specific chemicals used in manufacturing dyes, rubber, leather goods, paint, textiles, and hairdressing supplies may face higher chances of developing this cancer. These workplace exposures can occur over many years before cancer develops.[2][5]
Lynch syndrome, an inherited genetic condition, also raises the risk of transitional cell cancer. This syndrome increases the likelihood of several different types of cancer, including cancers of the urinary tract. People with a family history of Lynch syndrome should discuss screening options with their healthcare providers.[2]
The painkiller phenacetin, which caused kidney damage, was identified as a risk factor for transitional cell cancer. However, this medication has been off the market since the late 1980s and was not frequently used in the United States. No other painkillers have been associated with this particular cancer.[2]
Recognizing the Symptoms
Blood in the urine, medically called hematuria, is usually the first noticeable symptom of transitional cell cancer of the renal pelvis and ureter. This blood may make the urine appear pink, red, or cola-colored. Sometimes the amount of blood is so small that it can only be detected through laboratory testing, while other times it is clearly visible to the naked eye.[1][5]
Back pain represents another common symptom. This pain typically occurs on one side, in the area between the ribs and hip, sometimes called the flank. The pain may feel like a dull ache or sharp cramps. Some people also experience persistent pain in the lower back that does not seem to have an obvious cause.[2][5]
Many patients notice changes in their urination patterns. These can include pain or burning sensations when urinating, needing to urinate more frequently than usual, or feeling an urgent need to urinate even when the bladder is not full. These symptoms occur because the cancer can irritate the urinary tract or partially block the flow of urine.[2]
General symptoms may also appear, particularly as the disease progresses. These include unexplained weight loss, meaning weight drops without trying to lose it through diet or exercise. Persistent fatigue, feeling tired even after adequate rest, is another symptom. In some cases, a lump or mass may be felt in the kidney area during a physical examination.[2][5]
It is important to understand that symptoms may not appear right away in all cases. Sometimes transitional cell cancer of the renal pelvis and ureter is discovered during imaging tests performed for other medical reasons. This underscores the importance of seeking medical attention whenever unusual symptoms do appear.[5]
Prevention Strategies
Not smoking or quitting smoking if you currently smoke represents the single most effective way to reduce risk of developing transitional cell cancer of the renal pelvis and ureter. Because smoking is one of the strongest risk factors for this disease, avoiding tobacco use can significantly lower the chances of cancer developing. For people who already smoke, quitting at any age provides health benefits and reduces cancer risk.[5]
Avoiding exposure to harmful chemicals in the workplace offers another prevention strategy. People who work in industries involving dyes, rubber, leather, paint, textiles, or hairdressing supplies should use appropriate protective equipment and follow workplace safety guidelines. Proper ventilation and protective gear can minimize contact with potentially cancer-causing substances.[5]
For individuals with Lynch syndrome or a family history of urinary tract cancers, regular medical monitoring may help detect cancer at earlier, more treatable stages. While this does not prevent cancer from developing, it can lead to earlier diagnosis when treatment outcomes are generally better. Discussing screening options with a healthcare provider is advisable for people with known genetic risk factors.[2]
Maintaining awareness of personal risk factors helps people stay alert to potential warning signs. Those with a history of bladder cancer should be particularly vigilant about reporting any new symptoms to their doctors, given the elevated risk of developing upper urinary tract cancers. Regular follow-up care after bladder cancer treatment is essential.[1]
How the Disease Affects the Body
When transitional cell cancer develops in the renal pelvis or ureter, it begins as abnormal growth in the layer of cells lining these structures. Initially, the cancer may remain confined to just the inner lining. At this stage, it is considered superficial. More than 90 percent of patients with superficial cancer confined to the renal pelvis or ureter can be cured with treatment.[3]
As cancer progresses, it can grow deeper into the wall of the renal pelvis or ureter. The wall consists of multiple layers, including the inner lining, a layer of connective tissue, and a layer of muscle. Cancer that penetrates into these deeper layers is more serious. Patients with deeply invasive tumors that remain confined to the renal pelvis or ureter have only a 10 to 15 percent likelihood of cure.[3]
The depth of cancer infiltration into or through the wall represents the most important factor affecting prognosis at the time of diagnosis. Superficial tumors tend to be well-differentiated, meaning they look more like normal cells under a microscope. In contrast, cancers that have invaded deeply are usually poorly differentiated, appearing very abnormal and behaving more aggressively.[3]
In metastatic disease, cancer cells break away from the original tumor and travel through the bloodstream or lymphatic system to other parts of the body. Common sites of spread include the lungs, liver, bones, and lymph nodes. When cancer has penetrated through the wall of the renal pelvis or ureter or has spread to distant sites, it usually cannot be cured with currently available treatments.[3][8]
The cancer can disrupt normal urinary system function in several ways. Tumors may partially or completely block the flow of urine through the ureter, causing urine to back up into the kidney. This backup can damage kidney tissue and impair the kidney’s ability to filter blood and produce urine. Bleeding from the tumor into the urinary tract produces the blood in urine that many patients notice as their first symptom.[2]
Between two and four percent of patients develop cancer in the opposite kidney’s urinary tract, either at the same time or later. This can occur because the same risk factors that caused cancer in one location affect the entire urinary tract. Close monitoring of both sides is important during follow-up care.[3]